Circuit description: Notes
Platinum filament is used for the intake air flow meter SUB-ASSY. This SUB-ASSY consists of a heater made of platinum filament, temperature sensor, and control circuit, which are integrated into a housing. The heater equipped in the bypass flow duct of the housing is cooled by the intake air flow, and the temperature sensor detects the change in temperature. With respect to the circuit configuration, the bridge circuit comprises the heater and temperature sensor. The work of the power transistor to control heater to maintain the predetermined temperature (causing voltage difference between A and B) is measured as the output voltage of the intake airflow meter SUB-ASSY.
NOTE:
When either of these DTCs is stored, the engine control computer enters fail-safe mode. During fail-safe mode, the engine control computer calculates the ignition timing according to engine speed and throttle valve position. The engine control computer continues fail-safe mode operation until the normal condition is restored.
| DTC No. | DTC detection condition | Suspected parts |
|---|---|---|
| P0102 | Intake air flow meter SUB-ASSY voltage is 0.127 V or less for 0.5 seconds or longer. (1-trip detection logic) |
|
| P0103 | Intake air flow meter SUB-ASSY voltage is 4.723V or more for 0.5 seconds or longer. (1-trip detection logic) |
NOTE:
After checking diagnostic code outputs, read the following menu items using the SSM4: BRZ inspection / Each system / Engine / Data monitor / [Mass Air Flow]
| Intake air amount (g/s) | Content of malfunction |
|---|---|
| Approx. 0.0 |
|
| Approx. 655.35 |
|
CAUTION:
- Place the vehicle on a level surface in the workshop and check it with the engine stopped.
- Perform the inspection with the air cleaner ASSY installed.
- Do not use the exhaust duct to the exhaust tail pipe for suction.